Solved UPSC CDS/OTA Question
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Q · Optics-Reflection of LightMedium · 45s
Which device uses multiple plane mirrors to change the direction of light by 90°?
TopicOptics-Reflection of Light
Question Typemultiple choice
DifficultyMedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
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A periscope uses two plane mirrors inclined at 45° to the path of light to reflect it twice, changing its direction by 90°.
Final Answer: Option B - Periscope